Study On Performance Of Plasma Of Laser Induced Al/TiO₂ And Al/MnO₂ Multilayer Films

The mechanism of plasma characteristics of laser induced energetic multilayer in laser-driven flyer is focused in this paper,The effects of modulation period,laser pulse energy and delay time of TiO₂-Al,MnO₂-Al energetic multilayer on the laser induced TiO₂-Al and MnO₂-Al energetic multilayer were investigated.The effects of the laser pulse energy and the modulation period of the energetic multilayer on the velocity of TiO₂-Al-Al₂O₃-Al composite flyer and MnO₂-Al-Al₂O₃-Al composite flyer were investigated.TiO₂-Al?MnO₂-Al energetic multilayer and TiO₂-Al-Al₂O₃-Al and MnO₂-Al-Al₂O₃-Al composite films were prepared by magnetron sputtering.Respectively,the composite films were characterized by XRD,SEM.The results showed that the surface of the films were smooth and the interfaces between different layers were compact.The plasma characteristics of laser induced TiO₂-Al and MnO₂-Al composite films were studied by atomic emission spectroscopy.The result showed that the electron temperature of TiO₂-Al and MnO₂-Al thin films increases at first and then decreased with the increase of the delay time when the laser pulse energy is constant and the delay time is in the range of 0.50?s?1.9?s.The electron density of the TiO₂-Al and MnO₂-Al thin film decreases with the increase of the delay time.The electron temperature of TiO₂-Al and MnO₂-Al thin films increases at first and then decreased with the increase of the laser pulse energy when the delay time is constant and the laser pulse energy is in the range of 67mJ?224mJ.The electron density of the TiO₂-Al and MnO₂-Al thin film increases at first and then decreased with the increase of the laser pulse energy.The average velocity of flyer were measured by PVDF piezoelectric sensor.The velocity of composite flyers were measured by Photonic Doppler Velocimetry,the results showed that The results show that the velocity of TiO₂-Al-Al₂O₃-Al composite flyer and MnO₂-Al-Al₂O₃-A1 composite flyers can reach 6000m/s,and there was an optical laser energy threshold in velocity of the composite flyer.The velocity of the composite flyers would be improved by using the smaller modulation cycle of TiO₂-Al and MnO₂-Al films as ablation layer materials when the film thickness of ablation layer was constant.The research of the plasma characteristics and the performance of the composite films helps to understand the mechanism of the plasma characteristics in the laser-driven flyer technology,it has important significance to improving the laser-driven flyer technology,improving the laser energy coupling rate and practicality of laser-driven flyer technology.